The Executive Director of the Washington State Criminal Justice Training Commission says “public trust in American policing has been shaken.”

During a House Judiciary Committee hearing Tuesday on "Policing Strategies for the 21st Century," Sue Rahr said a national conversation on the culture and practices of policing has been sparked by the Ferguson, Missouri, shooting last summer and the release of disturbing videos every few weeks.

Rahr said there is no single description of U.S. police culture. She said there are 18,000 individual police departments, each taking direction from 18,000 local governments.

Milwaukee County, Wisconsin, Sheriff David Clarke told the committee police use of force should be scrutinized “in terms of factual data and circumstances.”

He said it should not be done “from an emotional foundation of false narratives or catchy slogans like ‘Hands Up, Don’t Shoot,’ or ‘No Justice, No Peace’ or ‘Black Lives Matter.’”

Clarke added “It is a myth that police kill black males in greater numbers than anyone else,” backing up the claim citing “a recent study” that examined police use of deadly force between 2009 and 2012. He said the study shows 61 percent of the 1,491 people who died from police use of force during that period were white males while 32 percent were black males.